Central air compressor kicking in but not staying on

As title states, the central air compressor is kicking in but not staying on for more than about ten seconds, and will try to start again in about 30 second or so.

The fan in the attic runs, but blows room temperature air. I made sure that it's not the overflow valve in the attic, and it seemed that one time when the system tried to work, it did bring down the return air temperature by a few degrees for about a half minute of so. All circuit breakers are on at the mail power to the house.

Problem started at the end of last year's cooling season so did not address it at that time, but as I recall, the stop was fairly sudden. I originally attributed it to low coolant, but the system is basically less than a year old (thanks to Hurricane Ike), so it should not have leaked that soon. It is hard to tell if it was a sudden death, as the system was not really cooling as much as just keeping the moisture down, since the temp inside and outside were pretty close.

Did not call anyone to check if there is enough coolant in the system as yet, because I'm hoping it's something simple I can do.